Tft substrate, liquid crystal display panel and liquid crystal display device having the substrate, and method of manufacturing tft substrate

Abstract

In a pixel ( 1 ), an oblique part of a capacitor line (Cs) includes a plurality of capacitor electrodes ( 2 a ) and a plurality of capacitor electrodes ( 2 b ), and the capacitor electrodes ( 2 b ) are provided between adjacent capacitor electrodes ( 2 a ). An insulating layer including an insulating film ( 6 ) is formed on the capacitor electrode ( 2 b ), and a pixel electrode ( 7 ) is further formed on the insulating layer. A voltage is applied across a liquid crystal between the capacitor electrode ( 2 a ) and the pixel electrode ( 7 ) so that a storage capacitance is formed which is defined by the capacitor electrode ( 2 b ) and the pixel electrode ( 7 ). By means of this, it is possible to achieve a TFT substrate, whose producing processes are simplified, for use in a liquid crystal display device in which electric field concentrating patterns of electrodes, via which a voltage is applied across a liquid crystal, are alternately provided at different heights in a thickness direction of a liquid crystal layer.

1 . A TFT substrate, for use in a liquid crystal display panel driven by a scanning signal line driving circuit and a data signal line driving circuit, comprising TFTs, scanning signal lines, and data signal lines, wherein, in each pixel:
 a plurality of first electrodes for applying voltage are provided along a substrate surface at intervals;   second electrodes for applying voltage are provided along the substrate surface, the second electrodes being provided between adjacent first electrodes so as to be at a higher height from the substrate surface than the first electrodes;   third electrodes that are connected to the first electrodes are provided, respectively, on the substrate surface side of the second electrodes; and   when a TFT turns on in response to a voltage via a scanning signal line, a data signal line is connected to a second electrode so that (i) a voltage is applied across a liquid crystal between the first electrodes and the second electrodes and (ii) no voltage is applied across the liquid crystal between the first electrodes and the third electrodes.   
   
   
       2 . The TFT substrate according to  claim 1 , wherein the third electrodes are provided on the substrate surface side of the second electrodes, via an insulating layer. 
   
   
       3 . A TFT substrate, for use in a liquid crystal display panel driven by a scanning signal line driving circuit and a data signal line driving circuit, comprising TFTs, scanning signal lines, and data signal lines, wherein, in each pixel:
 a plurality of first electrodes for applying voltage are provided along a substrate surface at intervals;   second electrodes for applying voltage are provided along the substrate surface, the second electrodes being provided between adjacent first electrodes so as to be at a higher height from the substrate surface than the first electrodes;   when a TFT turns on in response to a voltage via a scanning signal line, a data signal line is connected to a second electrode so that a voltage is applied across a liquid crystal between the first electrodes and the second electrodes; and   the first electrodes are transparent electrodes, and are provided so as to cover a protruding insulator and the substrate surface located around the insulator.   
   
   
       4 . A TFT substrate, for use in a liquid crystal display panel driven by a scanning signal line driving circuit and a data signal line driving circuit, comprising TFTs, scanning signal lines, and data signal lines, wherein, in each pixel:
 a plurality of first electrodes for applying voltage are provided along a substrate surface at intervals;   second electrodes for applying voltage are provided along the substrate surface, the second electrodes being provided between adjacent first electrodes so as to be at a higher height from the substrate surface than the first electrodes;   when a TFT turns on in response to a voltage via a scanning signal line, a data signal line is connected to a second electrode so that a voltage is applied across a liquid crystal between the first electrodes and the second electrodes; and   the first electrodes are transparent electrodes, and are provided so as to be in a planar form on the substrate surface between adjacent second electrodes.   
   
   
       5 . The TFT substrate according to  claim 1 , wherein the liquid crystal is a liquid crystal driven in a vertical alignment mode. 
   
   
       6 . The TFT substrate according to  claim 5 , wherein the liquid crystal layer has a thickness of not less than 2.8 μm and not more than 10 μm. 
   
   
       7 . A method for producing a TFT substrate recited in  claim 1 , comprising:
 concurrently forming, with a same material, the first electrodes, the third electrodes, the scanning signal lines, and gate electrodes of the TFTs; and   forming the second electrodes with the same material as the scanning signal lines after forming the first electrodes.   
   
   
       8 . The method according to  claim 7 , further comprising:
 concurrently forming, with a same material, (i) an insulating film which is part of an insulating layer between the second electrodes and the third electrodes and is subsequently formed after the third electrodes are formed and (ii) a gate insulating film of the TFTs.   
   
   
       9 . A liquid crystal display panel comprising a TFT substrate recited in  claim 1 . 
   
   
       10 . A liquid crystal display device comprising a liquid crystal display panel recited in  claim 9 . 
   
   
       11 . The liquid crystal display device according to  claim 10 , wherein:
 the liquid crystal display panel is composed of a combination of the TFT substrate and a counter substrate that does not include a counter electrode facing the TFT substrate; and   the liquid crystal is driven in an MVA mode.   
   
   
       12 . The liquid crystal display device according to  claim 11 , wherein:
 on the TFT substrate, the first electrodes and the second electrodes are provided along the substrate surface so as to run parallel to each other; and   the counter substrate does not include a structure for controlling an alignment of liquid crystal molecules.   
   
   
       13 . The liquid crystal display device according to  claim 11 , wherein no horizontal electric field parallel to the substrate surface that causes the liquid crystal molecules to align is generated in a region that (i) is between the first electrodes and the second electrodes and (ii) is closer to the substrate surface than the second electrodes.